Motorola PTP 400 Series - Manual (Page 63)

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7.7.10 Aligning the PTP 400 Series ODUs
The following is a description of the steps taken to establish a radio link between the two
units forming the bridge and align the units for the best signal strength.
The PTP 400 Series Bridge uses audible tones during installation to assist the installer with
alignment. The installer should adjust the alignment of the ODU in both azimuth and elevation
until highest pitch tone is achieved 13 . The tones and their meanings are as follows:
State Name Tone Description State Description Pitch Indication
(Higher pitch = higher
power)
Band Scan Regular beep Executing band scan N/A
Scanning Slow broken tone Not demodulating the
wanted signal Rx Power
Synchronized Fast broken tone Demodulating the wanted
signal Rx Power
Registered Solid tone Both Master and Slave
units exchanging Radio
layer MAC management
messages Rx Power
Table 10 - Audio indications from the ODU
The term ‘wanted signal’ refers to that of the peer unit being installed.
In each of the states detailed above the unit should be aligned to give the highest pitch tone.
It should be noted that if, when in the Synchronized or Registered state the tone varies wildly,
you may be suffering from interference or a fast fading link. Installing in this situation may not
give a reliable link. The cause of the problem should be investigated.
For the ease of alignment both Master and Slave units use the install tones in the same way
but with some small behavioral differences. This allows the installer to install the Slave unit
first and carry out the initial alignment with the Master unit if desired. However due to the
Behavioral differences of Master and Slave units it is recommended that the Master unit is
installed first and the initial alignment carried out at the Slave unit.
13 The pitch of the alignment tone is proportional to the power of the received wireless signals. The
best results are usually achieved by making small incremental movement in angular alignment.